Automatic telephone calling device.



I. G. BLESSING.

AUTOMATIC TELEPHONE CALLING DEVICE.

` APPLICATION FILED FEB. 2| I9I2. www

'1. G. MESSING;

AUTOMATIC TELEPHONE CALLING DEVICE. API'LICATIOII FILED FEB. 2'. 1912.

@I Q @MI/3g mi@ 1. G. BLesslNG.

AUTOMATIC TELEPHONE CALLING DEViCE.

APFfLICATION FILED FEB. 2. I9I 2.

,Q Patented Sept. 3,1918.

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`= JOHN G. BLESSING, OF CHICAGO, ILLINOS, ASSIGNOR TO AUTGMATIGELECTBIC COMPANY, F CHICAGO, ILLINOIS, A CORPORATION :OF ILLNQIS.

- nefasto.

"hecticn with 'automatic telephone systems.

Broadly, the objects of my invention are to simplify and improve the construction of such impulse-transmitting devices.

My invention. is particularly adapted for usejin connection with an automatic telephone systiem of the three-Wire -type-- that is, a system in which the impulses for operating the switches are transmitted first over'oneside of the line circuit and then 'over lthe other side of the line. ln systems of this character it is customary to transmit one or more impulses overone Aside of the line,` then,to transmit a series of impulses `overthe other side of the line, the number yof impulses in'this series depending upon the digit ot' the called number, and, then to follow each series of impulses by one or moreimpulses over the first side of the line. This operation is repeated for `each digit of the called number. vlt is also customary to transmit an impulse over' the two sides ot the line simultaneously upon the hanging up ofthe receiver for the purpose of releasing the central oice apparatus. This release impulse is some times produced by causing the dial of the-callingdevice'to move from a subnormal to a normal position upon the hanging up of the receiver. ln` constructing impulse-transmitting devices for such systems vit has been found diiiicult to construct a transmitter of small dimensions which would provide for this extra movement ot Athedial upon the hang ingup of the receiverand which would also provide a prolonged impulse over the first side of the line, which prolonged impulse isemployed or'causing the switches of the automatic system to perform certain opera tions. ln order to provide-a suiiiciently long impulse it4 was found necessary to give the i dial a greater angle of nficveinent.v lf the AUTOMAT-C TELEPHONE CALLING DEVECE.

Specification ci Letters mittenti.I Ermigte@ Sqgpg 3i ilgig Application filed February 2, i912. Serial No. 675,049.

size, it was impossibleto' have the dial accomplish all thatis required. with an angle of movement equal to yor less thanv three hundred and sixty degrees. One of the features of my invention is the overcoming ot' this objection by providing a dial which is capable. of rotating through an angle of more than three hundred and sixty degrees',V

While the impulse Wheel which is controlled by this dial still operates through an angle of less-than three hundred andl sixty idegrees. This increased angle of movement of the dial is made possible by means of an improved movable finger stop.

A further important feature oit my invention is the arrangement otthe dial and dial shaft separate and distinct from the rest of the mechanism, whereby this mechanism can be readily detached from the dial.`

A further 'feature is the provision' of a dial having a stationary series of characters or numbers to represent the irst series of impulses to be transmitted in calling a desiredsubscriber, in lcombination with a' movable series of characters or letters to represent the remaining or subsequent series of im pulses. A

These 'and other objects of my invention will be more readily understood by reference to the accompanying drawings, Whichl Figure l is avertical section of a desk telephone embodying the principles oit my invention, the section through the base being taken on the line l-l in Fig. 2.

Fig. 2 is a bottom View ,of the mounting plate in the base of the telephone.

inl

Fig. 3 is a top view of the dial inv normal position. l

Fig. 4 is a top View of the dial after it has been operated once. l

Fig. 5 is a view showing the normal relation of the impulse wheels and springs.

Figs. 6 to 17, inclusive, are diagrams shovvthe substation circuits.

anceA of thetelephone as a Whole is very much the same as that of an ordinary manual 'As shown in lfdueI general appear-- finger holes on the dial were kept of a given telephone, With the addition of the /autoin theopposite direction to that of the switch l1ook-that is,'when the switch hook moves upward, the-rod moves downward, and vice versa. The yhook switch springs 51, l55, 56 and 57 are" secured to the under side of the usual mounting vplate 2 inthe base of the telephone. The mountingplate 2 also forms a base for the mounting of the various parts of the automaticfcalling device, as well as for the induction coil 3 and the terminal Referring especiallyto Figs. 1 and 2, the automatic calling device is constructed as follows: Mounted in bearings on the upper t 6 side of the plate 2 there is a rotary sha upon which, near one end, there are secured two toothed impulse lwheels 7 and 8. Beneath these impulse wheels there is a pair of flexible impulse springs9 and 10, between lwhich there is a stationary ground post 11. The wheels 7 and 8 and portions of' the `springs 9 and 1'0 arer shown in elevation in Figs. 7, s, 1o, 11, 1e, 14, 1e and 17 inthe-- various positions which they assume in the. operation 'of the device. These figures are shown upside down so as to corres' ond with Fig. 2. Upon the upper side of t e springs 9 and 10 there are al couple of projections or lugs .12 and 13 which extend into the path of H rotation of the teeth ou the im use Wheels and 8, respectively. These impulse teeth are inclined to the planes of. the wheels, as arefalso the lugs 12 and 13 on the impulse springs. There are eleven teeth on the 'Wheel 8 and they ,are so inclined that as the wheel is rotated in aclockwise direction, as viewed in Fig. 8, or from the right, as shown in Fig. 2, each of e teeth on the wheel, as it passes the lug 1, on the spring 10, forces said sprin outward away from the ,ground post 11. s the wheel is rotated in the opposite direction, however, each of the teeth, as it passes vthe projection 13, momentarily forces the spring'lO into contact with-the ground post 11. There are only two teeth 14 and, 15 on the wheel 7.` The tooth 141 is so inclined that it forcesthe spring 9- into `engagement with the ground post only'when it passes the projection 12 in a counter-clock- ,wise direction. The two edges of the tooth 15 areinclined in opposite directions, so as to foroethe spring 9 into engagement with the ground post ll'when it passes the projection 12 in either direction. Loosely mounted upon theopposite end of the shaft 6 there is a gear wheel 17. This 'gear wheel is hol- .lowed out to form a shallow cup and ts over asecond gear wheel 18 whichis firmly secured to the shaft. The wheel 18 is provided with both spur and crown teeth. Se-

cured to the inside of the wheel 17 there is a spring pawl 19 which cooperates with the spur teeth on the wheel 18. The wheel 17 meshes with 'a pinion 20 which is secured to a Worm wheel 21., which latter in turn meshes'v with a worm 22 of a small governor comprising a pair of weighted springs 23 and a stationary cup 24. When the wheel 17 is rotatedthe springs 23 revolve and fly out and rub on the inner surface of the cup 2i,

the forward end of which is bent over into v the plane of a locking member 31 on the main shaft 6. A. small flat sprin 32 tends to turn the lever 30- on the shat 27 in a clockwise direction, the position of the lever 30 being limited by a small lug' 34 on the lower side of the lever. 28, which. lug extends across and beneath the rear end of the lever30. A coiled spring 33 on the shat- 27 Serves-to raise the lever 28 when the rod 29 is lifted by the depression of the switch hook:` When the receiver is on the switch hook; the lever28 is permitted to rise and tip the forward end of the lever 30 down, out of the path of the locking member 3.1. When the switch hook rises upon the removal of the receiver, the lever 28 is forced down, thereby-permitting the lever 30.to rise into the path ofthe member 31. The locking member 31 is beveled on one side so that when the shaft (l is rotated forward, with the lever 3() in-ittupper position, the membei' 31'may tip the end of the lever 30'down and pass itfbut will be arrested by said lever on the' return motion of `the shaft. Slidably mounted upon the under side of the late 2 by means or' the screws 35and 36 t ere is a bar 37. This har controls, through the medium of the insulating bushing 38, a couple of movable springs 39 and 40, The bar B7 is normally held in the position shown in Fig. 2, against the tension otI a small spring on its upper side, by a hook on the upper side of the end of the hook switch springl which normally engages the insulating bushing 58, and by a pin 42 in the impulse wheel 8. If the impulse wheel is rotated while the receiver is ofi' the hook, the bar 37 slides forward. Upon the initial movement of the bar 37 the spring 39 is permitted to come into contact with the ground post l1, and in the most-advanced position of the bar the spring 40 is forced out of,

Contact with the spring 10.

terreno i j The subscriber controls the operations or' the calling device through the medium of a diale which is provided with linger holes, and is secured to a shaft JA which is rotal tehly mounted in a platejl, which latter is' Ysecured over the top oftioun opening m the base of the telephone. Upon the lower end of the shaft 4A there Yis a gear wheel -l which meshes with the crown teeth of the wheel 18 on the shaft- 6. tween the plate and the gear wheel 46,

there is e clock spring; l?, one end of whichy is secused to thelshalit and the other to the plate. ,Secured to Athe top of the dial there vvis a number plate 2/.l bearing n number for each oil3 'the ting-er holes. Almn'iediately beneath the dial there is n finger stop 49. rl`his yfinger stop is loosely mounted upon the shaft finger stop 49, and after it'has orcedthe stop back against the upper edge of :the

notch in the casing' brings theclial to rest, as

p shown in 3.

The only connection between the dial and. the remainder ot the mechanism of the celling device .is that obtained through. the nechum of' the gear Wheels 46 and 18. it will thus be seen that by simply removing the screw i3() which 'holds the plete 45 in place,

ein

pair.

The general mode of operationel the callm0' device 1s as follows: Before malnne" a .Z3 call. the subscriber rst removes the receiver from the'switch hoog, whereupon the rod 29 is pulled down bythe springl, depressing' the spring 51. to unloelr the siiding bar 3i' and depressing the lever QS to permit the end of the lever 39 to rise into the nath of the locking member The subscriber now inserts his finger into e linger hole of the dial corresponding to the irst digit of the number to be nailed, sind rotates the dial until the inger is brought. to rest by the iinger stop diei the spring 45T is Wound up and the shaft 6 is rotated forward, hy reason of the engagement ofthe gear wheels lo and 1S. During this forward rotation of the shaft the pan/l. 19 slips over the top of the spur teeth of the wheel 18, thereby permitting the wheel 17 and governor to remain stationary. The normal relation of the impulse wheelsf and 8 and the springs 9 and 10 that shown in Figs. 'Y and 8. r)The normal relation the member 31 and the lever 30 after the switch hooi: is removed is es shown in Fir. 6. Upon the initial movement o the sli-att 6 pin l2 in the, wheel 8 per-g Around the shaft ll. be-` lluring this rotation ora the post 11. The impulse teeth 14 and then pass the projections 12 and 13 simultaneously, forcing the springs 9.and 10 outward and the bar 87 continues to move forward to its extreme position to separate the springs -LO and 10. As' the shaft 6 continues its forward motion the locking member lslips past the lever '30, and the tooth 15 on the impulse wheel 7 momentarily forces the;k spring 9 into contact with the ground j post 11'. The teeth on the impulse wheel 8 mits the bar 37 to slide forward suiciently 'to permit. the spring 3D to drop onto the next begin to pass the projection 13 on the the digit l. The finger is now removed from the dial and it, together with/the shaft 6.

*begins to be returned back toward normal position by the spring 47. During this backward rotation the pawl 19 engages the spur teethrof the wheel 18, so'as to bring the governor into play to'control the Spee During the return movement of the shaft 6 the impulse teeth pass the impulse springs in the vreverse order to that described above. Each tooth of the wheel 8, as it passes the projection 13, forces the spring 10 intomomentary contact with the post 11.l After the tooth 76 on the Wheel Spasses the projectionlO, the tooth 15 again passes the pro-f. jeetion 12 and momentarily forces the spring' 9 onto the groundpost. The shaft- Figs. V9, 10and 6 and impulse wheels do not return entirely l to their normal positions. but are brought to resiJ by the engagement of the member 3l and the lever 30 before the teeth 14 and 52 engz'xge the projections 12 and 13. vThis p osition of the apparat-us is. represented in yFigs. 12, 13 and 14. In this position of the apparatus the pin 42 forces the bar 37 back far enough to permit the springs 4,0 and 10 to come into engagement, but this does not occur .until afterA the impulse tooth 15 has permitted the spring 9 to break contact` with the post 11, nor isthe bar forced back far enough lto separate the springs 39 and 11. 'i

From the foregoing it vwill ybe seen that the complete operation of the dial for the digit' tirst causes the contact 3.9-11 to be closed, then the spring 9 is momentarily forced into contact with the ground post 11, after which the spring 10 is forced into contact with the ground post a number of times corresponding to the digit called, and

arated during the entire time the impulse springs are being operated The operethnie4v of the calling device for each of the digits after the first' oneis the same as has just been described, With the exception, of course,

' that the springs 39 end 11 are already in the switch hook, the lever Q8 is permitted to first removing the receiver.

rise and tip the forward end of the lever 30 down to release the member 31, thereby unlocking the impulse wheels and allowing them to make the short step from the position shown in Figs. 13 and 1i to normal, during which movement the teeth 1i und 52 simultaneously force the springs 9 and 10 into contactwith the ground post 11. This final movement of the impulse wheels torres the bar 37 back to' normal position to cause the springs 39 and 11 to be seperated. Figs. l5, 16 and 17y show the relative positions ot' various parts of the apparatus just after it las started. toward normal from the position represented in Figs. 12, 13 and 1i.

In order to aid in the understanding of the operation of thedevice, I have shown diagrummatically in Fig. 18 the essential features 'df thecalling device. In this figure the impulse wheels 7 and-8 are shown developed into the form of horizontal bers which may be moved longitudinelly through the medium of gearteeth on the periphery of the dial when said dial is rotated.

As has been explained, when the calling device is operated, the bar 87 cannot move forward to-permit the spring`39 to come into engagement with the ground post l1 unless thereceiver has first been removed from the switch hook, and it will thus be-seenlthat it. will he impossible to sendV in a call Without In large ex changes in whichthe'numbers of the subscribersllinesy comprise several di te, it is sometimes desirable to substitute e etter vfor the rst digit of each of the numbers,"so

that they may bel more easily remembered.

Since the letters are to be used for only the. first digit, it is not necessary that they be secured tothe dials of the calling devices,

but they mayl he placed on a stationair"` plate 115 beneath the dial in such a position that/they will be beneath the lproper finger holeswhen the dial is in its normal position. (.)f course, since the dial is not returned to normal position after. being once operated, these letters will appear to be shifted, as

shown in Fig. 4, after the first operation of the dial, but this Will produce no confusion, because the letters are lnot used after the first digit is called.

4The advantage of the movable form of finger' stop, as disclosed herein. over the `the proper movement of' the chosen,

Larissa than a complete revolution, and therefore allows the dial to be made smaller. since the space between the first und lust finger holes in the diei unifi' he mede smaller than would otherwise be the cese. is shown herein, the space between the. i und the No. O finger holes is aquel to the space occupied b v two hoies. It has been found desir-:ibis in telephone systei'ns that the i'otary impulses be longer than the vertical impulses. The rotary impulse tooth 15 is lon-g enough to produce an .impulse approximately twlce es long as the vertical impuises. This requires that the distance between the teeth sind 76 on the vertical impulse Wheel 8 be three times the pitch of the vertical impulse teeth, whence. in order to rotate the iirstfrerticsi impulse tooth '76 past its spring; 9, the iur pulse wheels must he rotated througfn, distance equai to four times the snguitr.v Ditch oi' the impulse teeth. ,Since s movement of brought to rest in what is the normei position of the No. 9 hole. This means that ii the finger stop were stationary it would have to be in front ot the No. 9 hole and wouid thus prevent the use of the last two holes in the diei. in order that the stationary stop Wouid not interfere with the use of the inst nger holes, the diei Awould have to be erilegged, so that .the space between the first an last holes' could be mede four times the pitch of the holes. so that the could be placed behind. the isst hole. With `the stop movabie, as shown herein,l it always remains behind the last hole, vet allows the finger to more past the'ncrmui vthe lust hole before being; brought to rest by it. Aithough, as shown, the spiace he tween the No. 1 ,and the No, G finger holes is equal to the spacecerupied by two hoies.' this space has been chosen urhitrsriiy. es it may be decreesed indefiniteiy, es long :is linger stop is and 18 is maintained such that a, rotation of the dini equal to the pitch of the tinger holes moves the impulse Wheels through a distance equal to the pitch of the vertical impulse teeth.

InFig. 19 there are shown the circuit. connections or n lccul battery e I telephone equipped with the ceiling device disclosed inger stop' position ci' and the ratio between the gears Sift i Il (l arebeing transmitted.v This is to prevent herein. The line condiietdr 60.and61 are directly connect d ttlief'finip'iilsel springs 9 and 10. The pringj39 is `connected `to ground, that `athen' thefContactjb'etn'feenA said springende e rearV portion of the spring 1l is closed' the latter spring is grounded.' vThus each time the springs 9v and.. 10a-re forced vinto contactvvvith the spr'ng'll during the operation of the calling devicegthe respective line conductors 60 and l are grounded.' The separation of the spring/t from the rear portion of the spring While the calling device is operating serves to open the talking bridge across the line conductors 60 andlwliile the impulses the impulses transmitted to one line conductor from passing to the other. 'The usual hooir switch comprising the springs 57, 56, and 5l -and the Contact point 62 is controlled by vthe switch hook through the medium. of the rod 29. At 64 there is sliovvn the usuel ringing; push button through the medium ot' which the called'subscriber is si aled after the connection is completed. ily the depression olc this button its spring is disengaged from the Contact point 65 and engaged with the Contact point 66, whereby the bridge across the line is opened and the line conductor is'groiinded.

While l have illustrated one particular form of my invention. it -is to be understood that I do not Wish to limit myself to the rexact construction shown `and described, as

many changes and modications will readily suggest themselves to those skilled in the art. t

What 'claiin as my invention isz- 1. ln a calling1 device. an impulse transmitter. a rotary dial controlling; said transmitter. means whereby said transmitting de vice transmits a single impulse during the forward rotation of the dial and a series of impulses during the backward rotation of the dial, and a stop movable each time the dial approaches the end ot its stroke for limiting the movement of said dial.

2. ln a calling device. an impulse transmitter. a dialior controllhier said transmitter. two conductors. means operating on the.

jforward rotation oi said ldial to cause said transmitter to transmit one ormore impulses over one of said conductors, means operated tipon the return of said dial to transmit ai series of impulses over the other oisaid' conductors. and a stop movable each time the dial approaches the end of its stroke tor limiting the forwardinovement of said dial. v y

3. ln a telephone, an 'impulse transmitter, a dial for. controlling said transmitter, means for moving' said dial forward to cause said transmitter to transmit a single impulse. means for returning said dial to a sub-normal position in advance of its nor- .inal position to cause said transmitter to transmit a. series of impulses, a switch hook associated with said transmitter, and means controlled by said switch hook' for returning said dial to its'normal position.

4. ln a telephone, an impulse transmitter, a dial for 4controlling said transmitter, means for moving said dial forward to cause said transmitter to'transmit a single impulse,y means for returning said dial toa sub-normal position in advance of its nor? mal position .to cause said transmitter `to associated with said transmitter, means con trolled by said switch hook for returning said dial to its normal position. and means for transmitting one or more impulses when lsaid transmitter passes from sub-normallto normal stopping point.

ln a Acalling device. an impulse transmittel', a dial for controlling the operation of said transmitter in accordance with a series .of characters, stationary charactersI representing the first character ot' said se# ries.,` and movable characters representing.r successivelyv the said series.

6. In a calling device, an impulse transl mittel'. a rotary dial having a series of finger holes, said dial adapted to be operated.I

a plurality of times in order to transmit a' plurality of Series of impulses, a stationary. series of characters representing the Afirst series of impulses transmitted, and a mov.-k able series of characters for representing the remaining series of impulses.

7. In a calling device. an impulse trans:-`

mit-ter, a rotary dial having,r a series of finger holes for controllingr said device. said dial adapted to be operated a plurality ot times in order to transmit a plurality of series of impulsesa stationary series ot characters arranged below said dial represeating the first of said series of impulses.

remaining characters bof transmita series of impulses, a switch hook and a second series of characters located on said dial and movable therewith for representing' the remaining series of impulses.

El'.v In a calling device, an impulse transmitter, a dial for controlling said transmitter. and a movable stoD for the dial, said Y dial being adapted to revolve through an angle of more than three hundred and sixty A degrees.

said stop operable inthe samedirection with ythe dial by the linger of the operator and by l the dial.

e 11. In a calling device, an impulse trans-- mitter, a dial having a series of finger holes for controlling said trans1nitter,.and a movablerstop for the dial, saiddial being adapt* ed to, revolve through an angle of over three hundred and sixty degrees, the said dial having a reciprocating motion,n the said stop operable lin one direction by the linger of the operator and in the other direction by the dial, but in the same direction with the dial in each case. y

12. In a calling device, a. reciprocating impulse transmitter having a normal and a sub-normal stopping point, and having a series of circuit closers, two conductors associated therewith, the circuit closers -being so arranged that when the transmitter is moved forward from the normal stopping point an impulse is sent over one of the cnyductors, and when the transmitter is moved the first conductor in each cycle of operation, being operable when the receiver is placed upon the Aswitch hook to release the latch and restore the transmitter to normal, some of the circuit closers operable Vupon such return to engage both the first and second conductors.

13. In a subscribers automatic telephone, a base, a dial mounted on the base, and impulse-sending mechanism mounted in the base separable from the dial and the base.

14. In a calling device, a rotary dial, a shaftupon which said dial impulse-transmitting mechanism controlled by said dial, said mechanism being separate and distinct from said dial and shaft, Whereby it can be readily detached therefrom.

15; In an automatic telephone, a base, an impulse transmitter in said base, adial for controlling said transmitter mounted on said base, a movable stop for the dial for limiting the stroke of the latter, said stop movable in the same direction with the dial, and means for removing the impulse transmitter from the base and disconnecting it from the dial. i Signed by me at Chicago, *Cook county, Illinois, this 29th day of January, 1912.

JOHN BLESSIN G.

'Witnessesz Amnvn J. RAY, Ammer nnnnnsau,

is mounted, and 

